diff --git a/util/econst.plt b/util/econst.plt
index 5044fd2..bd34395 100755
--- a/util/econst.plt
+++ b/util/econst.plt
@@ -1,9 +1,12 @@
 #!/bin/bash
-# econst.plt: plot <econst> in one or more MD simulations
-# use: econst.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-fit a*x+b "<grep -h econst $*" u 0:2 via a,b
-fit c "<grep -h econst $*" u 0:2 via c
-p "<grep -h econst $*" u 2 w l, a*x+b, c
+fit $range a*x+b "<grep -h econst $*" u 0:2 via a,b
+fit $range c "<grep -h econst $*" u 0:2 via c
+p $range "<grep -h econst $*" u 2 w l, a*x+b, c
 print "Econst_avg=",c,"   dE/dt=",a
 EOF
diff --git a/util/econst_cmp.plt b/util/econst_cmp.plt
index eb5174c..79894a2 100755
--- a/util/econst_cmp.plt
+++ b/util/econst_cmp.plt
@@ -1,6 +1,9 @@
 #!/bin/bash
-# econst_cmp.plt: compare <econst> in two MD simulations
-# use: econst_cmp.plt mdrun1.r mdrun2.r
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-plot "<grep '<econst>' $1" u 2 w l, "<grep '<econst>' $2" u 2 w l
+plot $range "<grep econst $1" u 2 w l, "<grep econst $2" u 2 w l
 EOF
diff --git a/util/econste.plt b/util/econste.plt
index 0828111..5498394 100755
--- a/util/econste.plt
+++ b/util/econste.plt
@@ -1,6 +1,9 @@
 #!/bin/bash
-# econste.plt: plot <econst> and <etotal> in one or more MD simulations
-# use: econste.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-p "<grep -h econst $*" u 2 w l, "<grep -h '<etotal>' $*" u 2 w l
+p $range "<grep -h econst $*" u 2 w l, "<grep -h '<etotal>' $*" u 2 w l
 EOF
diff --git a/util/econste_cp.plt b/util/econste_cp.plt
new file mode 100755
index 0000000..4bf04f2
--- /dev/null
+++ b/util/econste_cp.plt
@@ -0,0 +1,9 @@
+#!/bin/bash
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
+gnuplot -persist <<EOF
+p $range  "<grep -h econst $*" u 2 w l, "<grep -h '<etotal>' $*" u 2 w l, "<grep -h '<ekin_ec>' $*" u 2 w l
+EOF
diff --git a/util/eigsum.plt b/util/eigsum.plt
new file mode 100755
index 0000000..f6c445f
--- /dev/null
+++ b/util/eigsum.plt
@@ -0,0 +1,9 @@
+#!/bin/bash
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
+gnuplot -persist <<EOF
+plot $range "<grep -h eigenvalue_sum $*" u 2 w l
+EOF
diff --git a/util/enthalpy_int.plt b/util/enthalpy_int.plt
new file mode 100755
index 0000000..57ea069
--- /dev/null
+++ b/util/enthalpy_int.plt
@@ -0,0 +1,9 @@
+#!/bin/bash
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
+gnuplot -persist <<EOF
+plot $range "<grep -h enthalpy $*" u 2 w l
+EOF
diff --git a/util/etotal.plt b/util/etotal.plt
index 4805c58..c78bb8c 100755
--- a/util/etotal.plt
+++ b/util/etotal.plt
@@ -1,6 +1,9 @@
 #!/bin/bash
-# etotal.plt: plot <etotal> in one or more simulations
-# use: etotal.plt run1.r [run2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-plot "<grep -h '<etotal>' $*" u 2 w l
+plot $range "<grep -h '<etotal>' $*" u 2 w l
 EOF
diff --git a/util/etotal_cmp.plt b/util/etotal_cmp.plt
index ea4a3e0..f489b0c 100755
--- a/util/etotal_cmp.plt
+++ b/util/etotal_cmp.plt
@@ -1,7 +1,9 @@
 #!/bin/bash
-# etotal_cmp.plt: compare <etotal> in two MD simulations
-# use: etotal_cmp.plt mdrun1.r mdrun2.r
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-set grid
-plot "<grep '<etotal>' $1" u 2 w l, "<grep '<etotal>' $2" u 2 w l
+plot $range "<grep '<etotal>' $1" u 2 w l, "<grep '<etotal>' $2" u 2 w l
 EOF
diff --git a/util/etotal_int.plt b/util/etotal_int.plt
index 41b3f70..b8a409c 100755
--- a/util/etotal_int.plt
+++ b/util/etotal_int.plt
@@ -1,6 +1,10 @@
 #!/bin/bash
-# etotal_int.plt: plot <etotal_int> in one or more simulations
-# use: etotal_int.plt run1.r  [run2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-plot "<grep -h etotal $*" u 2 w l
+set grid
+plot $range "<grep -h etotal_int $*" u 2 w l
 EOF
diff --git a/util/etotal_int_cmp.plt b/util/etotal_int_cmp.plt
index 81ebd9d..8869c52 100755
--- a/util/etotal_int_cmp.plt
+++ b/util/etotal_int_cmp.plt
@@ -1,6 +1,9 @@
 #!/bin/bash
-# etotal_int_cmp.plt: compare <etotal_int> in two simulations
-# use: etotal_int_cmp.plt run1.r run2.r
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-plot "<grep '<etotal_int>' $1" u 2 w l, "<grep '<etotal_int>' $2" u 2 w l
+plot $range "<grep etotal $1" u 2 w l, "<grep etotal $2" u 2 w l
 EOF
diff --git a/util/force.plt b/util/force.plt
index a1bd09f..8edfc43 100755
--- a/util/force.plt
+++ b/util/force.plt
@@ -1,6 +1,9 @@
 #!/bin/bash
-# force.plt: plot all components of ionic forces in one or more simulations
-# use: force.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-p "<grep -h force $*" u 2, "" u 3, "" u 4, 0
+p $range "<grep -h force $*" u 2, "" u 3, "" u 4, 0
 EOF
diff --git a/util/sigma.plt b/util/sigma.plt
index 072e0ab..b6d5027 100755
--- a/util/sigma.plt
+++ b/util/sigma.plt
@@ -1,20 +1,11 @@
 #!/bin/bash
-# sigma.plt: plot stress tensor components in one or more simulations
-# use: sigma.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-plot "<grep -h sigma_xx $*" u 2 w l, "<grep -h sigma_yy $*" u 2 w l, \
+plot $range "<grep -h sigma_xx $*" u 2 w l, "<grep -h sigma_yy $*" u 2 w l, \
 "<grep -h sigma_zz $*" u 2 w l, "<grep -h sigma_xy $*" u 2 w l, \
 "<grep -h sigma_yz $*" u 2 w l, "<grep -h sigma_xz $*" u 2 w l, 0
-fit sxx "<grep -h '<sigma_xx' $*" u 0:2 via sxx
-fit syy "<grep -h '<sigma_yy' $*" u 0:2 via syy
-fit szz "<grep -h '<sigma_zz' $*" u 0:2 via szz
-fit sxy "<grep -h '<sigma_xy' $*" u 0:2 via sxy
-fit syz "<grep -h '<sigma_yz' $*" u 0:2 via syz
-fit sxz "<grep -h '<sigma_xz' $*" u 0:2 via sxz
-print "avg sxx: ", sxx
-print "avg syy: ", syy
-print "avg szz: ", szz
-print "avg sxy: ", sxy
-print "avg syz: ", syz
-print "avg sxz: ", sxz
 EOF
diff --git a/util/temp_ion.plt b/util/temp_ion.plt
index 74ad6be..8bb330c 100755
--- a/util/temp_ion.plt
+++ b/util/temp_ion.plt
@@ -1,9 +1,12 @@
 #!/bin/bash
-# temp_ion.plt: plot <temp_ion> in one or more MD simulations
-# use: temp_ion.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
-fit a*x+b "<grep -h temp_ion $*" u 0:2 via a,b
-fit c "<grep -h temp_ion $*" u 0:2 via c
-p "<grep -h temp_ion $*" u 2 w l, a*x+b, c
- print "Tavg=",c,"   dT/dt=",a
+fit $range a*x+b "<grep -h temp_ion $*" u 0:2 via a,b
+fit $range c "<grep -h temp_ion $*" u 0:2 via c
+p $range "<grep -h temp_ion $*" u 2 w l, a*x+b, c
+print "Tavg=",c,"   dT/dt=",a
 EOF
diff --git a/util/volume.plt b/util/volume.plt
index 38412be..64e8f4a 100755
--- a/util/volume.plt
+++ b/util/volume.plt
@@ -1,7 +1,10 @@
 #!/bin/bash
-# volume.plt: plot the unit cell volume during one or more MD simulations
-# use: volume.plt mdrun1.r [mdrun2.r ...]
+if [ $1 == "-range" ]
+then
+  range=$2
+  shift 2
+fi
 gnuplot -persist <<EOF
 set grid
-plot "<grep -h '<unit_cell_volume>' $*" u 2 w l
+plot $range "<grep -h '<unit_cell_volume>' $*" u 2 w l
 EOF